UPDATE 1-Trump's steel, aluminum tariffs exempt Canada, Mexico

By David LawderReuters

(Adds details on exemptions, background on opposition to plan)

WASHINGTON, March 8 (Reuters) - U.S. President Donald
Trump's tariffs on steel and aluminum imports will start in 15
days with initial exemptions for Canada and Mexico and the
possibility of alternatives for other countries, a senior
administration official said on Thursday.

The tariffs of 25 percent on steel and 10 percent on
aluminum, proclaimed by Trump on Thursday during an event at the
White House, appear to soften what the U.S. president billed
last week as a global, "no-exceptions" move to protect the two
industries under a 1962 national security trade law.

Trump's sudden push for the tariffs last week triggered
fears of a global trade war and rattled financial markets. U.S.
stocks pared gains on Thursday after the administration
official's comments.

The official told reporters the tariff proclamations will
allow other countries to discuss with the administration
"alternative ways" to address the national security threat
caused by their steel and aluminum exports to the United States,
the official said.

Asked whether these would include voluntary export
restraints, the official did not provide specifics, saying only
that the order could be "flexibly modified."

The tariff plan has angered U.S. allies, including Canada,
Mexico, Britain and members of the European Union, who argue
that their exports to the United States do not pose a threat to
U.S. national security. Some, including the EU, have threatened
retaliatory tariffs on U.S. products such as bourbon whiskey and
Harley-Davidson motorcycles.

"All countries will be welcome to discuss with the United
States alternative ways to address the threatened impairment of
the national security caused by their imports," the official
said.

The exemptions for Canada and Mexico would start immediately
with an unspecified duration. Their continuation depends partly
on progress in negotiations to modernize the North American Free
Trade Agreement, the official said. He added that NAFTA was an
important part of the U.S.-Canada-Mexico security relationship.

But the official said that with any alternative remedies, it
was important to maintain the target for increasing steel and
aluminum industry capacity utilization, which could result in
higher tariffs for other countries.

"If Canada and Mexico were to be excluded, we would perhaps
maybe have to raise the tariffs on everybody else - and modestly
I might add, modestly - to ensure that our steel and aluminum
industries are defended," he said.

The "wonderfully flexible document" is designed to
accommodate U.S. security relationships with other countries and
provide "ironclad" protections for the industry, he said.
(Reporting by David Lawder
Editing by Paul Simao)